The present invention generally relates to an electric lighting circuit and, more particularly, to a headlight lighting circuit for an automobile having at least one headlight of a type capable of being selectively exposed and concealed when the headlight is turned on and off, respectively.
Automobile headlights of a type capable of being selectively exposed and concealed when the headlights are turned on and off, respectively, which headlights will be hereinafter referred to as "concealable headlights", are currently employed in fairly recently developed fascinating models of automobile. In general, the concealable headlights now in use can possibly be classified into two types, namely, cover-up type and retractable type, depending upon how the headlight is concealed. The cover-up type is the one wherein the headlight, fixed in position in the front end of the body of the automobile, is concealed by a pivotally supported or foldable cover plate when the latter is moved to a closed position to cover the headlight whereas the retractable type is the one wherein the headlight is concealed or retracted into a lamp room in the front end of the automobile body.
In both types, the movement of the cover plate or the headlight selectively between exposed and concealed positions is effected by an electric motor operatively coupled thereto by means of a link mechanism. A conventional electric circuit for this drive motor includes a motor switch so ganged together with a headlight switch for the headlight that the switching on and off of the headlight switch to turn the headlight on and off can result in the movement of the cover plate or the headlight from the concealed position towards the exposed position and from the exposed position towards the concealed position, respectively.
The conventional circuit arrangement wherein the motor switch and the headlight switch are ganged together as hereinbefore described is very convenient in that there is no possibility that an automobile driver, after having turned one of the motor and headlight switches on, fails to turn the other of the motor and headlight switches on and vice versa. In other words, no separate manipulation of the motor and headlight switches is required.
While the conventional circuit arrangement has such an advantage in particular situations, it suffers from certain disadvantages which impair its utility in actual automobiles. By way of example, where the cover plate or the headlight is required to be held in the exposed position for the purpose of, for example, cleaning of the car or prevention of freezing of the cover plate in the concealed position, the headlight is simultaneously turned on even in those cases where no light is required.
In view of the above, it has long been considered desirable if the electric circuit is so designed as to enable the motor switch to be manipulatable independently of the headlight switch so that the cover plate or the headlight can be brought to the exposed position without the headlight being turned on and, simultaneously therewith, to enable the cover plate or the headlight to be brought to the exposed position when the headlight switch is turned on.